During Phase I of this project, Seraph Robotics will complete development and initial feasibility testing of a working prototype of a specialized 3D Printer Orthosis System for creation of multi-property custom foot orthoses. The methods to be employed include the selection of materials that are of the highest quality and have appropriate properties for the supporting and cushioning functions of 3D printed orthoses; development of a process for printing custom orthotics based on a clinician's prescription; and a small pilot study to compare the effects of orthotics created with Seraph technology vs. custom-molded foot orthotics on foot structure, function, and clinical outcomes in typically developing children with flexible flatfoot. Flatfoot is a medical condition in which the longitudinal arch of the foot is abnormally lowered, and may come into near or complete contact with the ground. If left untreated, pediatric flatfoot can result in permanent deformity as an adult, which makes mobility and exercise painful, thus increasing the risk of obesity and reduced cardiovascular health. The incidence of moderate-to-severe pediatric flatfoot is about 18% of the general population, and pediatric flexible flatfoot also has an extremely high (83%) prevalence in children with Down Syndrome, as well as in children who are overweight. Furthermore, more than half of all Americans have missed a day of work because of foot problems. Custom-molded, full-length orthotic inserts are commonly prescribed for pediatric flexible flatfoot patients, but current technologies to create these devices typically cost $200-$800 per pair, and have a manufacturing lead time of up to four weeks. Seraph's solution is a specialized, patent-pending additive manufacturing (3D Printing) system that utilizes digitized anatomical and clinical data to fabricate orthotics that can exhibit a wide range of precisely prescribed mechanical properties. The system being refined at Seraph offers advantages over manual fabrication and direct milling in speed, cost, control, and flexibility such as digitally varying the orthotic's compression properties (i.e., Young's Modulus) across different regions. Seraph's unique additive manufacturing process is able to alter physical properties by using specialized printing technology and materials, which will result in better, more effective foot orthoses. Seraph's system reduces waste and cost by eliminating manual labor from the manufacturing process and the expensive excess material discarded in subtractive, milling processes which carve orthotics from a solid block. Furthermore, if feasibility is shown with Seraph's technology in Phase I then the technology could be applied to create orthoses for individuals with pedal pathologies such as cerebral palsy in Phase II.